Sir Lionel was the younger son of King Bors
of Gannes (probably Vannes in Brittany) and Queen Evaine. He was named
from a birthmark shaped like a lion. After his father's death at the hands
of King Claudas, Lionel and his brother, Bors the
Younger, lived as captives at the usurper's court under the
tutelage of their father's old friend, Sir Pharien. They were eventually
rescued by the High-Priestess, Seraide, who turned them into greyhounds
and whisked them away to complete their education with their cousin, Sir
Lancelot, at the home of the Lady of the
Lake.

Lionel and Bors accompanied Lancelot to
Britain, where they became Knights of King Arthur's Round Table. One of
his first tasks was to act, along with Bors, Gawain
and Bedivere, as ambassador to the
Emperor Lucius during the Roman Wars. Upon his return, Lionel accepted
Lancelot's invitation to join him in adventure seeking. However, while
Lancelot slept, Lionel tried to help three knights fleeing from a single
adversary. All four were defeated by their opponent - a knight named
Turquine - and thrown naked into prison. Lionel had to wait some time for
release, since his companion was similarly imprisoned by the enchantress,
Morgan Le Fay.

At other times, Lionel helped in the search
for Sir Tristram; and then for Sir Lancelot, when he ran from the court in
a fit of madness, having argued with Queen Guinevere over his extra
curricula activities. During the Grail Quest, poor Lionel was captured by
two evil knights who stripped him naked, bound him and foot and dragged
him along the highway while thrashing him with thorns. His brother, Sir
Bors, saw encountered them, but was obliged to abandon any rescue in order
to save a nearby virgin from being raped. Unsurprisingly, Lionel was not
best pleased at his brother's actions and, when next the two met, he
threatened to run Bors through with his sword. Bors refused to defend
himself, until a hermit and then Sir Colgrevance, were slain trying to
break the two up. When he finally reached for his sword, a ball of fire
descended from Heaven to stop the fight.

Sir Lionel, of course, sided with Lancelot
when the schism with King Arthur opened up. He went with his cousin into
exile and was crowned King of Gaul. He, however, returned to Britain to
put down the last remnants of Sir Mordred's rebellion and was slain by the
latter's son, Melehan, with fifteen other knights while travelling from
Dover to London in search of Sir Lancelot.